my HTC windows phone 8x's screen display blacks out abruptly as i am doing my stuff and gives me a lot of hard time to make it display again. I need help. I also need to know what I did wrong to cause such a thing. Please help!

I am planning to buy this phone, its got really cheap now just 9000 RS INR or just 150 USD, so will it get windows 10 update?
windows 8.1 is available in India as well I suppose but if it gets windows 10,i think its a steal for the money,also have seen and used this phone, nothing beats HTC in terms of built quality,design,looks,appeal,so sorry to see this design didnt get an android installed in it, neverthless, please reply, any chance of windows 10 for HTC 8X